Articles, Blog

Why Are Mosquitoes Attracted To You?!

Why Are Mosquitoes Attracted To You?!


Are you the person in the group who’s always getting bitten by mosquitoes? Because I certainly am and science has shown that this is a thing – that mosquitoes are more attracted to some people than others. And the reason for that is at least partially genetic, which is why this video is supported by 23andMe, a company that reads sections of your genetic code and then helps you understand, what’s in there. Now, they’ve actually been involved in some research that has identified particular spots on your DNA that make you more or less likely to be attractive to mosquitoes, and in this video I want to put that to the test. So I flew to New Mexico State University to meet mosquito man Professor Immo Hansen. Everyone: Hello! Hansen: We have a collection of lab strains Derek: Here, he maintains colonies of many different species of mosquitoes, and one exotic strain he actually feeds with his own blood(!) Hansen: No, no, I’m serious. These ones are made from my blood. D: Really!?
H: Yes! Absolutely, yeah. D: You feed these!?
H: And I’m the only one feeding them – I can’t ask my students, you know, that would be a nightmare H: getting permissions to this room here.
D: How do you blood feed them? D: With just, sticking your arm in there?
H: Well, I just put my arm in there and wait D: Is it psychologically itchy or…?
H: No it is really itchy [laughs] H: Yeah, and I’m getting, I mean, 25 bites or so right now D: Mosquitoes need our blood proteins to make their eggs, so only the female mosquitoes bite. The eggs hatch into these wriggly larvae, which develop into pupae before becoming flying, adult mosquitoes. Then they, once again, seek out vertebrate blood to make more eggs. The whole lifecycle takes just two weeks! But what I wanted to know is: am I a desirable target? D: How can we figure out if I’m attractive to mosquitoes? H: Okay, we have a Y-tube, basically, which has a holding chamber. We put the mosquitoes down here, H: there’s a little fan inducing a draft, something like 4 m/s. We’re gonna insert a bait into one of these chambers, in the green or the yellow one. D: So, by bait, you’re saying me?
H: Yes, you, exactly.
D: [laughs] H: You put your hand in there. [It] would be good if you would rub your hand first, so H: If you’re sweaty…
D: Get some oils?
H: Yes! D: This is the right spot…
H: That’s where the good stuff is, exactly. H: Almost feeds exclusively on humans. They are really specialized on biting humans. D: That’s good to know…
H: Yeah
[both laugh] H: There’s 20 mosquitoes in the holding chamber. D: And they’re gonna decide whether to come and find me, or go down the other side and… they find nothing. H: Right.
D: We’re releasing the mosquitoes. I see them coming! D: Oh, he’s chosen wrong! H: Do you see that? H: Man, you are attractive! D: Really?
H: I mean, sorry I-
[both laugh] H: You are a strong attractant to mosquitoes. They all went in your direction.
D: None of them went the other way! D: (laughing) This is amazing! H: Well, there’s one stranded in here
D: I did not expect to have such a strong… response, like D: You see all those mosquitoes… D: This type of test was actually used to discover that the basis for our attractiveness to mosquitoes is at least partially genetic. Researchers recruited 18 pairs of identical female twins and 19 pairs of non identical, or fraternal female twins. Then they used the Y-tube Test to evaluate the mosquito attractiveness of each individual, measured by the fraction of mosquitoes who correctly flew to the arm of the tube where the twin was standing. What scientists found is that the mosquito attractiveness of twins is correlated, that is, the more attractive you are to mosquitoes, the more likely your twin is, too. But that’s… not all that surprising, and could be caused by environmental factors, or a common diet. But, comparing identical twins to fraternal twins revealed the correlation was higher for identical twins. This strongly suggests genetics influence how attractive you are to mosquitoes. Since the identical twins share more of the same genes than fraternal twins, this explains why their mosquito attractiveness would be more closely correlated if it really is genetics that determines how much mosquitoes like you. D: With that last test, I was clearly attractive to these mosquitoes.
H: Yes.
D: Except we weren’t comparing me to any other human, D: we were just comparing me to a control, no human.
H: Exactly, yes. D: So, what if we compare myself with my wife Raquel? [laughs]
H: Uh-huh? D: Normally, I get bitten and she doesn’t.
H: Okay.
D: So this should be a good test… maybe? D: To see whether under lab conditions… H: We can we reproduce your…
D: We’ll reproduce our anecdotal finding. That I’m more attractive.
H: Exactly, anecdotal evidence a little once again H: They are a little…
D: Once again… D: …preparing. H: Okay!
D: Hands in position!
Raquel: Yeah. H: Yeah, see, they actually start to wake up. They… smelled something. Something’s going on here.
R: Here we go. H: Okay.
D: What are we seein’? D: Whoa! D: I’m getting a good amount over here, but so are you? D: Let’s see. I think I’m getting more. It looks to me like you got three. H: Okay, I’m gonna stop the experiment right now.
D: Alright. H: *chuck!* Okay, now let’s count. I think it’s seven on your side here? Lab assistant: Five in the holding.
H: Five in the holding. H: And quite a few on your side!
[Hansen and Derek laugh] H: So, who gets bitten?
D: I get bitten.
H: You get bitten! H: In reality, we would repeat this experiment, maybe eight times or so. D: Right.
H: And switching you guys around, but I think this is a good way to show how this works. D: Okay, so that result was not particularly scientifically rigorous, but it did reproduce our experience in the wild, D: which is that I am much more attractive. ….Well at least when it comes to mosquitoes, than Raquel. D: But the question is, I guess, does this come down to our genetics? R: Yeah, so, we spat into some tubes and sent them off to be tested.
D: Right, and we were interested in seven particular D: locations on our DNA, which were located in a 2017 study that involved 23andMe. D: So the way 23andMe works is, when you sign up, you can opt in to be part of research, D: and 16 000 people agreed to be part of this study and rate their perceived attractiveness to mosquitoes. D: So then what the scientists did was a genome-wide association study, that is, they looked at all the DNA D: of all of those participants and tried to see if there were commonalities amongst the people who D: said they were attractive to mosquitoes and that were different to the people who said they weren’t attractive to mosquitoes. D: And they identified seven particular locations on the DNA. Seven single letter changes which seemed D: to be associated with different levels of attractiveness to mosquitoes. D: So we have our results back, and do you wanna see them?
R: I do. I do, I’m very curious. D: Alright, let’s pull it up here. D: Okay, so of the seven locations that are related to mosquito attractiveness, it turns out we have the identical DNA at four of them. D: So you can rule those out.
R: Okay.
D: Which leaves only three areas where we actually have differing D: DNA. So, at the first location, you have one copy of a letter change which actually makes you significantly D: *protected* from mosquitoes.
R: Oh, no way! D: Yeah, it’s associated with decreased attractive to mosquitoes
R: Oh, that’s cool! D: I do not have any letter changes at that location. Now, at the second location where we differ, I have D: a letter change compared to you that makes *me* less attractive to mosquitoes, so more protected. R: Interesting.
D: If you look at the significance of those two letter changes, D: yours is about twice as significant than mine.
R: Okay. D: But still we both have a protective letter switch. So, in the last snip we actually differ significantly. D: And I have two copies of a variant that makes me more attractive to mosquitoes. D: This was the only snip which was associated with being more attractive to mosquitoes, D: and I have two copies of that change, and you have no copies of that change. R: So that makes sense.
D: So overall, I would say our genetics really adds up here. D: And of course, we can’t say that this proves that it is right, but it is definitely consistent D: with these snips actually being associated with your attractiveness to mosquitoes, and that’s sort of… D: borne out by our experience.
R: That’s so cool! D: Now, it’s unclear exactly how these genetic changes might make us more or less attractive to mosquitoes, but it’s likely that it has something to do with the odor or the volatile chemicals that our bodies give off, and due to the microbiome, the bacteria on our skin. One of the main signals that mosquitoes like to follow is carbon dioxide. So that means if you have a higher metabolism, or if you’ve just been exercising, or if you’re a bigger person, or even if you’re pregnant, you are more likely to attract mosquitoes. But mosquitoes are also attracted to some other volatiles that we give off, things like lactic acid, acetone and ammonia. But scientists have also found some chemicals that repel, or appear to impair mosquitoes’ ability to find us. Those chemicals we naturally give off are octanal, nonanal, decanal, and 6-methyl-5-hepten-2-one. So, why is this important? Well the researchers estimate that our attractiveness to mosquitoes is about as hereditary as height or IQ, that is to say genetics play a significant role here, so understanding that relationship is really important, especially when you consider that, of all the animals, mosquitoes have the greatest impact on human health. D: Are mosquitoes the worst animal of all time for humans?
H: Absolutely. H: Absolutely, there’s no question about that. Malaria has killed more people than people have killed people. They are the most dangerous animal in the world. D: By some estimates, mosquitoes have killed more than half of the humans who have ever lived. Now, that estimate has been debated and is likely too high, but even so, this year, over a million people will die of mosquito-borne illnesses. So if not half, certainly a significant number of humans have died due to mosquitoes, probably more than any other single cause, which led me to wonder: D: Do you think humans may have evolved this trait to smell worse to mosquitoes as an adaptation to avoid the diseases? Or… D: is it just by accident that some people are less attractive to mosquitoes than others? H: ……. H: …That is a really good question!
[both laugh] D: And while we’re on the subject of evolution, consider this: if you ever contract malaria, it actually changes your body chemistry to make you produce an odor that makes you more attractive to mosquitoes. Think about that! The malaria parasite has evolved so that, when it’s in its host, it makes the host more attractive to mosquitoes… mosquitoes are the thing that transmit malaria! It’s phenomenal! I mean evolution is incredible! [Veritasium logo] This episode of veritasium is supported by 23andMe, a company whose name comes from the fact that humans have 23 pairs of chromosomes, and the point of the company is to help people understand what’s written in your chromosomes. Now, at the minute, you can’t get access to the mosquito attractiveness test, but maybe, one day in the future, you will be able to. Right now, you can access tons of information about your physical traits, about aspects of your health, and about where you DNA and, I guess, you come from. So I thought I would share my results with you. I come from all over the world as you can see from the map, but significantly more from Europe, about 95% European. You can drill down into that and see that I’m largely British and Irish, and French and German, with a bit of Scandinavian. What’s interesting to me is, there’s a 3.3% South Asian which is something I think my family suspected, but didn’t know for sure, so it’s interesting the types of information you can find out which is stored in your DNA. So, if you wanna find out about the information in your DNA, you can go to 23andme.com/veritasium. So I want to thank 23andMe for supporting Veritasium, and I want to thank you for watching.

Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

100 thoughts on “Why Are Mosquitoes Attracted To You?!

  1. So with that 'malaria makes you more attractive to mosquitos' thing, what the mosquitos are doing is dousing you with 'mossie ketchup' to make you more delicious. Great…

  2. Mosquitos ruin every moment for me, whenever i try to enjoy myself out at nature, a mosquito comes and joins me for some of blood

  3. I am a filipino now living in korea. When I was in Philippines, I was the one who mosquitos really, and I mean really love to bite. When I came here in korea. I noticed that mosquitoes don’t bother me that much compared to my korean co workers who gets attacked by dozens of mosquitoes. Maybe the genetics of mosquitoes also should be considered in this studies. Cause they might be choosing also based on their gene preferences.

  4. when you love meat too much and wont eat your electric foods and vegetables then your bound to invite mosquitoes

  5. 🌈🦋 Can you comment on the effectiveness of the new machine emits different kinds of light including UV that supposedly stops itch because the heat of it kills the bacteria that bug leaves in your skin that makes it itch-can it help free venting Lyme disease?🙂🙃

  6. I don’t have the same issue with mosquitoes as you do but when I was younger and any of our pets had fleas I was the one who got bit a lot .

  7. These YouTube faggots just love to think they are going to make it big someday. Hey faggot anybody can do what ur doing. Keep sucking dick and shut the hell up

  8. I actually currently have 20 mosquito bites on my legs r.n
    NO JOKE so if your wondering that's what happens when you fall asleep outside

  9. one side benefit I've noticed after started smoking tobacco is that mosquitoes are no longer attracted to me! I used to miss sleep so often because of these little shits, and use to itch my skin until it bled all day long. I guess tobacco ain't so bad after all.

  10. I was watching this video with my headphones on and whenever a mosquito made that "hmmmmmm" sound in the video, I thought it's around my head…😂🤣😂

  11. If the malaria bacteria has already done it's job, so to speak, by infecting its host, how does the bacteria benefit by causing the host to attract more mosquitos?

  12. Now I need to know why my new mosquito bites don't itch until a week later. I got ate up 1.5 weeks ago and didn't start itching until 4 days ago. I forgot all about the bites and then I realized just how much I got bit that night.

  13. OK then, genetics play a role. What about diet, or if you're sweating? One thing for sure is that even if you're one of those who are least attractive to squitos, if you're the only one around they'll go for you too! They're looking for blood, and mammals who breathe out carbon dioxide are definite blood babies, especially since we're mostly hairless. Your dog or cat have too much fur for them to bother with. Thank goodness they're not as smart as bedbugs, who also love your blood.

  14. I'm always in my backyard using my telescope every summer in Melbourne Australia and never got bitten but one summer (2013).. I kept getting bitten like crazy ….so maybe not just genetics coz that one summer it was close to unbearable…maybe they had slim pickings that year???….lol….Who knows….

  15. When I walk outside, all mosquitoes stop biting, they throw up, just so they can fly and bite me instead. Even thou I infront of their eyes murder their kind, they still want me.

  16. My ex must be really attractive to mosquitoes since she always had exactly one mosquito bite on each her left and right chest.

  17. I think our genes would change over time because of mosquitoes to be less attracted to them, just from the fact that the people that are attractive to mosquitoes would have a more likelihood of dying, and so the people that are less attractive to mosquitoes would have a more likely chance to pass on their genes

  18. Mosquitoes are annoying but they're on of the most interesting animals ever, amongst insects. We need them more than we think, and I believe we should focus more on how we're destroying the planet and everything on it rather than the organisms that are just living out their lives.

  19. You made a mistake they are not mosquitoes they are Vampires and they dont suck the Bite and suck 50% of your blood same time

  20. Heck I could be outside for less than 2 minutes and I get bitten up to five times. And I'm not just attractive to mosquitoes but anything that sucks blood

  21. One way to avoid getting bitten by mosquitoes and other bloodsuckers as much is 2 I either eat lots of garlic or take garlic pills

  22. WHY CAN I NOT GET THE SAME REPORT AS YOU ABOUT MY DNA?
    AND I BELIEVE THAT MALARIA PROVES EVOLUTION BULLSPIT IS NOT EVOLUTION AT ALL, JUST LIKE THE IDEA THAT BEES HAVE EVOLVED TO KNOW TO ATTACK CO2 IS NOT EVOLUTION IT IS JUST THE WAY THINGS ARE, NOT THAT IT HAS EVOLVED BUT THAT GOD CREATED THING ON THIS EARTH WITH MANY VAST AND MAGNIFICENT ATTRIBUTES AND ABILITIES, JUST AS WE MIGHT ADAPT TO OUR SPECIFIC CLIMATE OR HABITAT ACCORDINGLY FOR OUR OWN SURVIVAL. THAT DOESNT MEAN WE EVOLVED IT MEANS WE PERSIST. LIFE ISNT EVOLVING, WE AS LIFE-LIKE OTHER FORMS OF LIFE ARE HERE BECAUSE WE PERSIST AND REFUSE TO DIE, OUR CREATOR KNEW THE FUTURE AND WHAT WE MAY NEED AND SO WE HAVE BEEN GIVEN THE BIOLOGICAL ATTRIBUTES TO PERSIST UNTIL THE CHRIST HAS RETURNED. SCIENCE IS COOL, BUT SCIENCE IS NOT GOD NOR SHOULD IT BE A RELIGION. SCIENCE PROVES GOD AND HOW THE MYSTERIES OF GOD ARE SO ASTOUNDING. SO I SAY EVOLUTION, NO I DID NOT COME FROM A MONKEY, WHY ARE THERE STILL MONKEYS? I SEE WHY YOU HAVE BEEN CHOSEN TO GROW AS HIGH AS YOU HAVE WITH YOUR CHANNEL. I LIKE YOUR CONTENT, BUT THEN YOU GO AND PUT THAT DARWINISM SERPENT IN THE GARDEN LIES AND SPINNING IT INTO THIS SUPERSTITIOUS AGNOSTIC NONSENSE THAT JUST BELITTLES YOUR ENTIRE BODY OF WORK.

    ALL I'M SAYING IS STAY TRUE TO THE SCIENCE, DONT SELL OUT TO THOSE WHO WOULD HAVE YOU PROMOTING THEIR WORLD VIEW THROUGH THEIR EXTRA FUNDING OF YOUR WORKS. BETTER TO STAY POOR AND STAY REAL. THAN RICH AND LOOSE THE GROUND UPON WHICH THY DOES WALK UPON.

  23. "How do I figure out if I'm someone who attracts mosquitoes?" Ah that's a tough one. I would definitely go to a lab for that. But for the smart ones in the crowd – I mean those with a life, stuff to do, you know – unless you get attacked by them, I wouldn't worry about it.

  24. You lost me at evolution. Which more or less identities similarities yet no one knows what they actually mean or do. Sure we can identify many thing aligned with patterns but doesnt remotely show that nothing designed itself to be something. 😕 A bit illogical dont you think?

  25. U say octenol is a substance we naturally give off that repels mosquitoes. But then why does the mosquito magnet that I have use it as an attractant for catching them?

  26. Surely there are safer ways too feed mosquito's your blood. Blood soaked spongy tissue of some kind… Pork?

    Exsanguinated before being injected with subjects blood…

    Or maybe just a sponge.

    Ps. I'm a bumpkin, not a scientist.

    *Edit: The pig probably needs to be kept alive. Transanguination?

    Schizoids make up words.

  27. My brother had his DNA analysed at 23 and me, and it said that he was only 1% English, but, his parents, grand parents all generations that we know of were English. I actually can't understand how they could get it so wrong.

  28. mosquitoes are also attracted to me, but i hate them and i enjoy killing them and i also enjoy pour bleach into water ponds.

  29. How is that happening? I'd heard of microbes and other things affecting the behaviors of the host but this is wierd.

Leave a Reply

Your email address will not be published. Required fields are marked *